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In response to Alexandre Rodrigues: When the systems are large and complex, as real systems tend to be, a single optimization may not help - the arguments of why we employ simulations in the first place would apply to optimizations too. Traditional arguments are: you cannot control a real system bas...

Here are some references for solid waste generation. Have fun! Chikte, S. D., and Lewis, A. H. (1976). =93A Dynamic Simulation Model= of Urban Litter Generation.=94 I. E. E. E. Transactions on System Man a= nd Cybernetics, SMC-6(May). Mashayekhi, A. N. (1992). =93Transistion in the New York State so...

There may be something of interest for you in my dissertation work - "Environment and Development - A Study of North-South Conflict". While I did not deal with electric utilities, I did use system dynamics and game theory (both static and dynamic) to explore conflict issues arising from po...

At 09:04 AM 3/8/97 +0100, Roberto Vacca Wrote: >Dear Jaideep: I think there are serios fallacies hidden n the paucity of >data acceptance. At ISIS, Rome, Italy we use SD, but never alone. After >major drives to get data & assess their quality, we use lgistic >substitution models [based on Volter...

This is a very interesting and useful discussion. I have a few points/clarifications to add: 1. I agree structure of the model is very important - but if its output is not checked with real data, then this structure is as limited as the mental model that produced it. I dont know if any research has ...

Thanks for your detailed reply Alexandre. I am pretty much in agreement with you, as you may see from my post on the list. I think accurate data, accurate relationships, and accurate structure - all are important - we cannot religiously stick to only the structure argument and thus arouse the wrath ...

Barry Richmond viewed CLD vs stock-flow debate as a set of 3 skills in progression, essential to what he calls systems thinking: 1. system-as-cause thinking (ala GPRs "endogenous viewpoint"); 2. closed-loop thinking (this is where CLD come in); 3. operational thinking (this is where stocks...

Thanks all for responding to my email. I have no problems with the new and very user-friendly perspective that SD provides to understanding and controlling complex systems (I am already sold, so you dont have to convince me;-)). My concern is that one can teach a whole course in SD without ever ment...

Dear John, Sounds indeed very interesting. >As background, it is worth pointing out that the Australian water >industry has been undergoing dramatic change including restructuring >and privatisation. As a result there is a lot of interest in industry >regulation and comparative performance. Raison d...

Dear Friends, Please respond if you have any info on system dynamics applications in water/wastewater management and/or in sewer rehabilitation area. Looking (of course, this is a SD list!) not at hydraulic engineering models, but at policy analysis SD models, preferably with socio-political dynamic...

Hi Iqbal, There are many on this list who can comment more on your queries than I can. From my limited experience, I can say I also found using stocks and flows much easier to start with than the causal-loop approach (I learnt it the hard way). Somehow the latter became murky very quickly, and the o...

First of all, it is an honor to get a reply from you, Dr. Forrester. By raising the "fun" issue, I did not mean that having fun while learning was bad in some sense, only that sometimes the tendency to make subjects fun makes explanations too simplistic, without demanding serious effort fr...

In response to Jim Hines, two places where >"adjusting the last bits of some parameter values >just to get it right! (while feeling confident in the model structure)"? may be important. First: you (intuitively or otherwise) know that the system behavior is very sensitive to 2 or 3 critical...

Greetings everyone I will try to respond to Dr Richardsons (GR) and John Holdens (JH) emails in my message here. I believe GR was responding to some recent queries such as "how do i start in system dynamics/Stella and how do I use it in my graduate work??". GRs response is to work in this ...